Is it possible to somehow limit the speed of some wifi clients using sqm rules or something similar, and not create news ssid for this, it's not very convenient. As far as I know, for example, ubiquity routers allow you to set multiple passwords for a single ssid, and depending on which password is entered, the corresponding policies will be applied.
Absolutely. The GUI should allow you to set rules per, IP, port, etc.
In the GUI, in the settings of the SQM QoS, I can only select an interface such as LAN,WAN or WiFi, but I cannot select a specific device that I would like to restrict. To do this, need to create a new interface, for example Wifi_new, which I think is not very convenient
I'm sure there are many ways to do this, but you can use OpenNDS to manage it for you.
You create a list of mac addresses, with upload rate, download rate, upload data limit and download data limit. You also set a fair usage policy restriction that throttles the data rate if the set volume is exceeded.
Any clients not in the list get a captive portal login screen.